Angular Momentum - 1

For linear motion, we found it very
useful to describe motion in terms of the (linear)
momentum,

p = m
v

Momentum was important because momentum
is conserved. That is the total amount of momentum of a
system is a constant.

In a similar manner, we will define the
angular momentumL of an object as

Angular momentum = (rotational mass)
x (angular velocity)

L = I

Like linear momentum, angular momentum is important
-- and interesting! -- because angular momentum is conserved!
That means the value of the angular momentum remains constant. We can often
change the "rotational mass" or the "moment of inertia". This will cause the
angular velocity
to change to keep the angular momentul L at its original value.

This can give a whole new meaning to the
phrase "dizzy Physics professor".

Remember conservation of angular
momentum the next time you watch a gymnast, a diver, a
ballerina, or an ice skater!